1. Field of the Invention
The present invention relates to a power supply circuit including a voltage regulator and a headphone driving circuit employing the same, and more particularly to a power supply circuit including a voltage regulator and a headphone driving circuit employing the same comprise the voltage regulator capable of stably providing a positive power supply and a negative power supply to an amplifier included in the headphone driving circuit.
2. Description of the Related Art
A headphone driving circuit comprises an operational amplifier amplifying an audio signal.
When the operational amplifier requiring a positive power supply and a negative power supply is used, the positive power supply is converted to the negative power supply to drive the operational amplifier.
The negative power supply obtained from converting the positive power supply is unstable, and a constitution of a circuit for converting the positive power supply is very complicated.
In addition, since a differential signal should be applied to the operational amplifier, the operational amplifier requires a balanced signal path for isolating a noise form an input signal to be amplified.